docs: def render(self, context, instance, placeholder):
          ''' Allows this plugin to use templates designed for a list of locations. '''
          context = super(StatsGraphPlugin,self).render(context,instance,placeholder)
  
          # Javascript makes it difficult to calculate date/time differences, so instead
          # pass the most useful ones to the template context in a dictionary.  These are used
          # to show stats over different time ranges.
          limitMonthDates = {}
          for m in range(0,25):
              limitMonthDates[m] = (timezone.now() - relativedelta(months=m)).strftime('%Y-%m-%d')
  
          # The same for graphs that allow one to choose different years.
          recentYears = [timezone.now().year + x for x in range(-5,1)]
  
          series_by_year = Series.objects.order_by('year')
  
          if series_by_year.count() > 0:
              first_year = series_by_year.first().year
              allYears = [x for x in range(first_year,timezone.now().year + 1)]
          else:
              allYears = []
  
          context.update({
              'limitMonthDates': limitMonthDates,
              'recentYears': recentYears,
              'allYears': allYears,
          })
          return context